import java.util.*;

public class Main6 {
    public static void main(String[] args)
    {
        Scanner cin = new Scanner(System.in);
        int n = cin.nextInt();

        int hash[] = new int[n+1];
        int k = 1;
        while(k != 0)
        {
            k = cin.nextInt();
            hash[k]++;
        }
        int t =0;
        for(int i =1;i<=n;i++)
        {
            if(hash[i]==0)
            {
                System.out.print(i + " ");
                t++;
            }
        }
        if(t==0)
            System.out.print("FULL");


        cin.close();
    }
}